Whatever provocation there may be, nobody can launch a physical assault. If you were confident of the evidence in the form of CCTV footage showing the physical assault on you, you could have lodged a police complaint immediately after the incident. By now, the employer might have erased that particular clip from the records.
Apart from filing a police complaint, you could have handled the matter differently. You could have resigned and completed the clearance from the company. Now, the employer might turn the tables against you, as your case could be deemed as "Abandonment of Employment."
Even now, you can go back and complete the separation process and then claim the dues. If your employer refuses to pay, legal action can be taken.
Thanks,
Dinesh Divekar